Telephone solicitations, especially those that are not based on a prior relationship, or "cold calls", are often very time consuming and inefficient for both the calling and the called party. With respect to the calling party, or telemarketer, a great deal of time is wasted on unproductive phone calls, such as to called parties that are not at home or who are not receptive to such calls. With respect to the called party, or potential consumer, undesired solicitations can be an annoyance, especially at certain times of the day or night.
Typically, the attempted efforts to alleviate the above described problems have been directed to the potential consumer. In particular, the efforts have been centered around the calling parties identification number (CLID). For example, many local exchange companies provide an "anonymous call blocking" service which blocks calls with anonymous CLID's. However, this service has several problems. For one, it may block too many calls, such as calls from out-of-state pay phones and the like. For another, many telemarketers buy telecommunication lines that have no CLID. The anonymous call blocking service does not block these calls.